Petrol Gauge

[lowfat55]

Hi, I have a 1997 CD 1800 Carina. Two Problems I have, 1. The fuel / petrol gauge acts weird the needle drops all the way down past the empty mark i.e clock wise six o'clock then it will go back again where it was positioned before the drop. Someone said the sender unit might need a clean ?

2. My rear windscreen wiper stopped working on delayed action Why! it works on constant fine but every now and then it don't ? Is there a electrical connection / contact on the rear hatch somewhere ? Can anybody help